title: Hydrogen multicenter bond mediated magnetism in Co doped ZnO.
abstract: Magnetism in Co doped ZnO (ZnO:Co) is strongly affected by the presence of the ZnO's extrinsic impurities, such as unintentional hydrogen dopants. Our ab initio investigation reveals that in ZnO:Co the formation of substitutional H (H(O)) with four-fold hydrogenic bonds is favored over interstitial hydrogen (H(I)) by 0.4 eV. It is found that H(O) is trapped by Co ions to form highly stable Co-H(O)-Co complexes. H(O) also mediates a strong short-ranged ferromagnetic interaction between Co dopants via short-range exchange interaction which induces room temperature ferromagnetism.
authors.affiliation: School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: M H N
authors.initials: MH
authors.lastname: Assadi
authors.forename: Y B
authors.initials: YB
authors.lastname: Zhang
authors.forename: S
authors.initials: S
authors.lastname: Li